Woodwind instruments are musical instruments that produce sound when a player blows air against an edge or opening of the instrument, causing the air to vibrate within a resonator. The name woodwind stems from the material used to blow air against. Although many woodwind instruments are still made from wood, certain woodwind instruments may now utilize metal or plastics.
Woodwind instruments include single reed instruments, double reed instruments and flutes. A reed is a thinly sliced piece of wood (typically cane) or plastic, over which a player blows. Single reed instruments use a reed that is held against the aperture of a mouthpiece with a ligature. When air is forced between the reed and the mouthpiece, the reed vibrates, creating the sound. Single reed instruments include clarinets and saxophones.
A ligature of a single reed instrument usually extends circumferentially around the entire outer body of the mouthpiece to hold the reed in place on the mouthpiece. Typically, screws are used to tighten the circumference of the ligature in conformance with the general shape of the mouthpiece and outer face of the reed in order to secure the reed to the mouthpiece. Because of the mechanical coupling between the ligature, the mouthpiece, and the reed, the structure of the ligature plays a role in the sound produced by the instruments.